Permanent magnetic core device

Abstract

Biased core devices and method of use are disclosed in which magnetic core energy losses due to hysteresis and eddy currents are greatly reduced in comparison to the core losses in prior art transformers and inductive devices. The present invention sets forth a transformer or choke device in which permanent magnets are surrounded by electrical steel materials and may be held in place by pole pieces. The magnetic core transformer structure also permits a method of use in which current passing through the device is controlled by the field strength of the permanent magnets. In addition, the biased magnetic core transformer operation may be linear or non-linear, and placed in series or parallel within a circuit. The magnetic components disclosed in the present invention affords both energy loss reductions and size reductions in comparison to known prior art transformers. The invention has many applications, including, but not limited to, the protection of switch gear, current limiting, voltage transformation in power distribution and for current control in arc discharge lamp circuits.

Description

FIELD OF THE INVENTION[0001]The present invention relates to the field of magnetic inductors or transformers and, in particular, relates to an inductor or transformer with a permanent magnetic core or biased core technology.BACKGROUND OF THE INVENTION[0002]Magnetic amplifiers have been well known in the art for use in power control systems. Magnetic amplifiers rely on the fact that magnetic fields or magnetic bias are created in the magnetic circuits of inductive power components so as to effect the control of current or power. It is known in the prior art to construct magnetic inductors containing an iron core, such as disclosed in U.S. Pat. Nos. 4,103,221 and 4,009,460, both to Fukui et al. However, when an inductor utilizes a ferromagnetic core for example, the core is readily capable of reaching magnetic saturation, due to DC electric current, resulting in a reduction of the inductance. To avoid these saturation problems, Fukui et al. proposes to utilize permanent magnetic cores...

AI Technical Summary

Benefits of technology

[0004]It is a feature of the present invention to provide inductor devices which are highly energy efficient and produce low amounts of heat.

[0005]It is another feature of the present invention to provide inductor devices which are lightweight and compact.

Problems solved by technology

However, the devices as described by Fukui et al. form a solid core structure, and are thus still heavy and are not well adapted for devices where a reduction of weight is critical.

In addition, the devices of Fukui generally do not maintain a precise and steady level of flux density or saturation, throughout a wide range of DC current.

Furthermore, the device of Fukui are specifically designed for DC current applications, and do not appear to be effective in AC current applications.

Images